Aircraft must be able to fly safely with no malfunction or upset caused during a cruising flight or during landing and takeoff under high intensity radiated fields (HIRF) as an electromagnetic environment from radios, televisions, radars, emitters and other sources. Therefore, HIRF protection measures required in (14CFR) SS23.1308, 25.1317, 27.1317, and 29.1317, High-intensity Radiated Fields (HIRF) protection, which stipulates Regulations (airworthiness requirements) of FAA (Federal Aviation Administration) need to be taken.
Recently, the importance of protection of electric/electronic systems of aircraft has been significantly increasing because of the following reasons:    1) a greater dependence on electric/electronic systems that execute required functions for continued safe flight and landing and takeoff of aircraft;    2) a decrease in electromagnetic shielding by a certain type of composite material used in design of aircraft;    3) an increase in susceptibility (sensitivity) of electric/electronic systems to HIRF along with increases in operating speed of data buses or processors, density of ICs or cards, and sensitivity of electronics;    4) an expansion of a usage frequency particularly to a high-frequency band of 1 GHz or more;    5) an increase in severity of an HIRF environment along with an increase in the number of RF transmitters and electric power; and    6) an adverse effect on part of aircraft when exposed to HIRF.
Meanwhile, inside aircraft, there may be an adverse effect on, for example, communications with an airport control tower, and communications or control of navigation for a flight along a predetermined route due to radio waves or electromagnetic noise (simply referred to as electromagnetic noise below) from various electronics such as mobile phones, game machines, and notebook computers, or PEDs (Personal Electro Devices) such as active-type RFID (Radio Frequency IDentification) tags attached to air cargos. Thus, as is well known, passengers are asked to refrain from using various electronics inside aircraft.
Since airframes of aircraft are generally formed of a metal material, electromagnetic noise enters and exits a cockpit (a flight deck) and an avionics bay from a cabin (a seat space) mainly through a cabin window and a cockpit window. To prevent the electromagnetic noise that possibly causes a failure from entering the cockpit or the avionics bay, a film of ITO (Indium Tin Oxide), gold, silver or the like is provided so as to be inserted into the cabin window obtained by laminating a plurality of window panels made of acrylic or the like (e.g., see Patent Literature 1).
As shown in FIG. 5, a window 100 includes a window section 102, and an outer retainer 103 that surrounds an entire outer peripheral portion of the window section 102.
The window section 102 includes a plurality of, (three in the present embodiment) laminated window panels 104A to 104C.
Resin films 105A and 105B made of PVB (polyvinyl butyral) or the like are respectively sandwiched between the window panels 104A and 104B, and between the window panels 104B and 104C.
An electromagnetic shielding film 106 is sandwiched between the resin film 105A and the window panel 104B. The electromagnetic shielding film 106 is a thin film formed of a conductive material such as ITO, gold and silver.
One end 107a of a conductive tape 107 is adhered to an outer peripheral portion of the electromagnetic shielding film 106. The other end 107b of the conductive tape 107 projects to the outer peripheral side from the window section 102, and is bent along an outer peripheral end surface 102a of the window section 102.
A second conductive tape 108 is adhered to the outer peripheral end surface 102a of the window section 102 so as to cover the other end 107b of the conductive tape 107. The second conductive tape 108 is bent along the outer retainer 103. The second conductive tape 108 is attached and grounded to a grounding area 107B formed in the outer retainer 103.
Accordingly, the electromagnetic shielding film 106 is electrically connected to an airframe 110 via a pin 111 that connects the conductive tape 107 and the second conductive tape 108 to the outer retainer 103, and the outer retainer 103 to the airframe 110. The electromagnetic shielding film 106 is electrically connected to the airframe 110 as described above to thereby express an electromagnetic shielding effect.
A weather seal 109 made of silicone sealant or the like is also provided so as to cover the second conductive tape 108 provided on the outer peripheral end surface 102a of the window section 102. An environment-resistant seal for acquiring waterproofness, moisture proofness, and airtightness is thereby obtained.